(19)
(11) EP 0 905 731 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
12.01.2000 Bulletin 2000/02

(43) Date of publication A2:
31.03.1999 Bulletin 1999/13

(21) Application number: 98117852.8

(22) Date of filing: 21.09.1998
(51) International Patent Classification (IPC)7: H01H 33/66
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 30.09.1997 JP 26538197

(71) Applicants:
  • Hitachi, Ltd.
    Chiyoda-ku, Tokyo 101-8010 (JP)
  • Kuze Bellows Kogyosho Co, Ltd.
    Kahoku-gun, Ishikawa 929-0343 (JP)

(72) Inventors:
  • Morita, Ayumu
    Hitachi-shi, Ibaraki 316-0032 (JP)
  • Tanimizu, Toru
    Hitachi-shi, Ibaraki 319-1222 (JP)
  • Horikoshi, Toshio
    Fujioka-shi, Gunma 375-0041 (JP)
  • Yotsumoto, Yoshiharu
    Tokyo 123-0851 (JP)
  • Hashimoto, Takanori
    Kahoku-gun, Ishikawa 929-0326 (JP)

(74) Representative: Strehl Schübel-Hopf & Partner 
Maximilianstrasse 54
80538 München
80538 München (DE)

   


(54) Bellows and vacuum switch using the bellows


(57) A bellows of which one end portion is fixed to a movable lever 35 passing through a vessel wall and swinging and the other end portion is fixed to the vessel wall 3 is characterized in that the spring constant of the above-mentioned bellows at a central portion in an expansion direction is made smaller than that at the end portions in the expansion direction. The bellows can damp stress concentration at end portions and improve the life, without enlarging the size of the bellows.
And a vacuum switch has the bellows used therein.






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